Incident Overview
On the flight immediately preceding the accident, an instructor and a student had successfully executed a forced landing to the airport following a partial power loss. After landing, the instructor noted a drop in RPM on the magnetos—1000 RPM on the left and 500 RPM on the right—and observed that the engine was running rough at idle on both magnetos. The instructor reported the landing and engine problem to front desk personnel at the fixed-base operator (FBO).
Sequence of Events
Shortly after the report, the same aircraft was signed out to a 17-year-old student pilot for a solo flight. Witnesses reported hearing the engine running rough, and two witnesses stated that the engine quit. They further described the airplane maneuvering at approximately 100 feet altitude, heading toward a dirt road, when it nosed down while in a left bank.
Pre-Flight Instructions
Prior to departing, the student was instructed by the dispatcher and an unidentified instructor to perform a "good engine run up" and to lean out the mixture to "clear the plugs."
Engine Examination
An examination of the engine revealed a chafed plug lead that had been routed around a primer line. Additionally, fouled plugs were found on the majority of the cylinders.
Probable Cause
The source does not state a probable cause.